Supplementary Material for: Vitamin D Supplementation Modulates the Immune System and Improves Atopic Dermatitis in Children

Background: Vitamin D seems to influence the evolution of atopic dermatitis (AD) in children. Methods: We tested the vitamin D serum levels of 39 children with AD (AD group t₀) and of 20 nonallergic healthy controls (C group). AD severity was evaluated using the AD scoring system (SCORAD index). Cytokine serum levels (IL-2, IL-4, IL-6, IFN-γ, TNF-α) and atopy biomarkers were also measured. The patients were then treated with vitamin D oral supplementation of 1,000 IU/day (25 mg/day) for 3 months. We then reevaluated the vitamin D serum levels, AD severity and cytokine serum levels in all of the treated children (AD group t₁). Results: The cross-sectional analysis on patients affected by AD (AD group t₀) showed that the initial levels of all the tested cytokines except for TNF-α were higher than those of the healthy control group (C group), falling outside the normal range. After 3 months of supplementation the patients had significantly increased vitamin D levels (from 22.97 ± 8.03 to 29.41 ± 10.73 ng/ml; p = 0.01). A concomitant significant reduction of both the SCORAD index (46.13 ± 15.68 at the first visit vs. 22.57 ± 15.28 at the second visit; p < 0.001) and of all the altered cytokines (IL-2, IL-4, IL-6, IFN-γ) was also found. Conclusions: This study showed vitamin D supplementation to be an effective treatment in reducing AD severity in children through normalization of the Th1 and Th2 interleukin serum pattern.